JPS5924711A - Rubber-modified graft thermoplastic resin composition - Google Patents

Abstract

PURPOSE:A thermoplastic composition excellent in impact resistance, tensile strength, and appearance of molding, prepared by graft-polymerizing a specified polybutadiene or random butadiene copolymer with a vinylaromatic compound. CONSTITUTION:In a butadiene copolymer obtained by a reaction between a tin halide compound and a butadienyllithium-terminated polybutadiene or random butadiene copolymer comprising a vinylaromatic compound and 1,3-butadiene, obtained by using an organolithium compound as an initiator; 2-40pts.wt. copolymer, of which the bound aromatic content is 0-30wt%, the vinyl bond content of the butadiene portion is 70-30wt%, and the content of a branched butadiene copolymer in which the bond of the branched portion is a tin-butadienyl bond is 20-80wt%, is grafted with 98-60pts.wt. vinylaromatic compound or a mixture of a vinylaromatic compound with at least one copolymerizable vinyl monomer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermoplastic resin composition reinforced with a rubbery polymer having a specific branched structure.

More specifically, the present invention relates to a rubber-modified thermoplastic resin composition obtained by graft polymerization of a vinyl aromatic compound or a vinyl aromatic compound and a vinyl copolymer copolymerizable therewith.

Styrene polymers or styrene reinforced with rubbery polymers
Acrylonitrile copolymers have excellent impact resistance, mechanical properties, and processability (they are used in many fields as plastics with lances).

These styrene polymers or styrene-acrylonitrile copolymers having excellent impact resistance are industrially produced by polymerization methods such as bulk polymerization, suspension polymerization, solution polymerization, and bulk-suspension polymerization. In this method, polybutadiene rubber, styrene-butadiene copolymer comb, etc. are used as toughening agents, but in particular polybutadiene rubber obtained by solution polymerization has traditionally been used to impart excellent impact resistance at room and low temperatures. It has been widely used.

However, when styrene polymers using polybutadiene as a toughening agent and styrene-acrylonitrile copolymers are made into injection molded products, the appearance of the molded products, such as colorability and gloss, is inferior.
Also, weld dry/ is easily noticeable. Furthermore, when it is made into a sheet molded product, its tensile strength and stiffness are slightly inferior. Polymerization operations can also be carried out in bulk polymerization, suspension polymerization, or bulk polymerization.
When polymerizing by suspension polymerization, solution polymerization of polybutadiene in styrene solution or styrene or acrylonitrile solution has disadvantages such as high solution viscosity.

On the other hand, when styrene-butadiene random copolymer is used as a toughening agent, tensile strength, stiffness, extrusion processability,
Although the appearance of molded products such as colorability and gloss is improved, impact resistance has to be sacrificed. In addition, there were problems such as a slight bonding area called a weld line remaining during injection molding.

Styrene polymer or styrene with rubber as a toughening agent
There are many factors that determine the physical properties and appearance of an acrylonitrile copolymer, and they are intricately related to each other, but among them, the dispersion state of the rubber in the plastic matrix, that is, the particle size and its degree of crosslinking are important factors.

As a result of the inventors' intensive study focusing on these factors,
By using these styrene polymers and copolymers containing styrene polymers as toughening agents, resins with surprisingly excellent impact resistance, high tensile strength, and excellent molded appearance, especially gloss, can be obtained. Heading The invention has been completed.

The method of the present invention will be specifically explained below.

The rubbery polymer used in the present invention is a butadiene copolymer obtained by reacting a random butadiene copolymer consisting of an organic ritinyl aromatic compound and 1,3-butadiene) and a tin rogenide compound. 1) The bound vinyl aromatic compound content of the copolymer is O~
(11) The vinyl bond content of the butadiene moiety of the copolymer is less than 10% -1 = 301, and (11) a branched butadiene system in which the bond of the D branched moiety is a tin-butadienyl bond; Proportion of copolymer As the organic lithium compound of the present invention, known ones such as propyllithium, n-butyllithium, 5eC-butyllithium, tert-butyllithium, amyllithium, etc. are used.As the hydrocarbon solvent, hexane, Heptane, cyclohexane, etc. are used.

Examples of tin halide compounds include methyl tric 00 tin,
Butyltrichlorotin, octyltrichlorotin, methyltribromotin, tetrachlorotin, tetrabromotin, etc. are used.

A method for producing a branched butadiene copolymer having a tin-butadienyl bond is to add 5 to 500 moles of 1,3-butadiene per 1 atomic equivalent of lithium at the polymer terminal of a random butadiene copolymer with a lithium atom terminal. It can be obtained by adding a tin halide compound from.

In order to exhibit the effects of excellent impact resistance, high tensile strength, and excellent molding appearance of the rubber modified graph I/thermoplastic resin composition of the present invention, it is necessary to The union is a specific metal-carbon bond, that is, a tin-butadienyl bond, and the branched butadiene copolymer is contained in the butadiene copolymer in an amount of 20 to 8.0% by weight, preferably 30 to 70% by weight. It is necessary to include it at a ratio of If the bond in the branched bond portion is a carbon-carbon bond bonded with divinylbenzene or a silicon-carbon bond bonded with silicon tetrachloride, the surface gloss decreases and the molded appearance is not good. If the proportion of the branched butadiene copolymer in the butadiene copolymer is less than 20% by weight or more than 80% by weight, the surface gloss will decrease and the molded appearance will not be good.

The vinyl aromatic compound of the present invention includes styrene, p-methylstyrene, vinyltoluene, 3,5-dimethylstyrene, etc., but styrene is preferred. In the random copolymer of 1,3-butadiene and a vinyl aromatic compound, the content of the vinyl aromatic compound is 0 to 30 parts by weight, preferably 4 parts by weight to less than 15 parts by weight. Ichiban 4 Shizome-1
If the weight exceeds -30, the impact resistance will decrease.

Moreover, the random copolymer of the present invention is 1. M, Ko-11
, hoff et al. [J, Polymer Sc
The content of the blocked polyvinyl aromatic compound in the bonded vinyl aromatic compound according to Vol. If the content of the block polyvinyl aromatic compound exceeds 20% by weight, the impact resistance will be poor.

The vinyl bond content of the butadiene moiety of the butadiene copolymer of the present invention is less than 10% and less than 304%, preferably 1%.
The number is 5 or more and less than 30.

If the vinyl binder content is 30% or more, the impact resistance at low temperatures will be poor, and if it is less than 10%, it will be difficult to manufacture.

Mooney viscosity (MT,
, +4) is 20 to 100, the ratio of weight average molecular weight (M, ) to number average molecular weight (M, ) M, /M. is preferably less than 2.5. If the Mooney viscosity is less than 20, the impact resistance and tensile strength are poor, and if the Mooney viscosity exceeds 100 or M, 7M, is 2.5 or more, a butadiene copolymer is dissolved in the monomer to form a rubber-modified graft. When producing a thermoplastic resin, the solution viscosity becomes high, which is not convenient.

The monomers used in graft polymerization in the presence of a butadiene copolymer are vinyl aromatic compounds such as styrene, p-methylstyrene, vinyltoluene, α-methylstyrene, etc. It is a mixture of at least one polymerizable vinyl monomer. Vinyl monomers that can be copolymerized with vinyl aromatic compounds include vinyl cyanide compounds such as acrylonitrile and methacrylate, acrylic esters such as methyl methacrylate and ethyl acrylate, and acrylamide derivatives. are used in combination of two or more. By selecting a specific monomer from these vinyl monomers and using it in combination with a vinyl aromatic compound,
A rubber-modified grafted thermoplastic resin paste product with excellent transparency can be obtained. In particular, since the composition of the present invention has excellent surface gloss, it has low diffused reflection of surface light and good transparency. A particularly preferred monomer in the present invention is styrene or a mixture of styrene/acrylonitrile (weight ratio: 100
10 to 60/40) are used.

The mixing ratio of the rubbery polymer and the monomer mixture is such that the rubbery polymer accounts for 2 to 40% by weight of the total resin composition. 2
If it is less than 40% by weight, the impact resistance will decrease, and if it exceeds 40% by weight, the viscosity of the polymerization solution will become very high, making polymerization substantially difficult.

In the present invention, the rubber-modified graft thermoplastic resin composition can be produced batchwise or continuously by bulk polymerization, solution polymerization, suspension polymerization, or a combination thereof. A so-called graphite or soft polymer which is prepared separately and blended with the rubber-modified grafted thermoplastic resin composition obtained in the present invention is a polymer or copolymer of at least one monomer selected from the above-mentioned monomers. It is also possible to impart the effects of the present invention to a rubber-modified thermoplastic resin composition obtained by a blending method.

Next, the present invention will be explained in more detail with reference to Examples. The rubbery polymer used in the present invention was produced as follows.

Cyclohexane 125 (
125Of H', n-hexane, 652g of 1,3-butadiene and 35g of styrene as the first monomers, and 27g of tetrahydrofuran were added, and after adjusting the temperature inside the reactor to 60°C, n-butyllithium was added. 37
F was charged and polymerization was started. After polymerizing at 60°C for 10 minutes, a mixture of 1,3-butadiene 335-f and styrene 15f was added as the second monomer to 102
Polymerization was carried out at 60° C. for 35 minutes. 1 as the third charged monomer
, 3-butadiene was continuously supplied to the reactor at a ratio of 52/+, polymerization was carried out at 60° C. for 10 minutes.

Thereafter, 0.175 F of tin tetrachloride was added and a coupling reaction was carried out at 60°C for 30 minutes. Polymer solution [2,6-
After adding 2.52 g of ditert-butyl-p-cresol and desolventing by steam stripping,
A copolymer was obtained by drying with a hot roll at 110°C.

Polymer 13 1 as the first monomer charged in the method of Polymer A
．． The same procedure as for Polymer A was carried out except that 3-butadiene 757, styrene 25V, and 1,3-butadiene 350V were used as the second monomer charge.

Polymer (1 as the first monomer charged in the method of Polymer A)
, 3-butadiene 502, styrene 5゜2, 1,3-butadiene 33or as the second monomer charge
, Styrene 202, and tin tetrachloride 0.180 t were used in the same manner as the method for Polymer A.

Polymer 1) 1 as the first monomer charged in the method of Polymer A
, 3-butadiene 302, styrene 702, and 1,3-butadiene 1952 and styrene 155 g as the second monomers.

The same procedure as for Polymer A was carried out, except that 100 tons of 1,3-butadiene was used as the final monomer, and 1,3-butadiene 3507 was used as the second monomer.

Polymer F The same procedure as for Polymer A was carried out except that 0,005 t of tin tetrachloride was used.

Polymer G The same method as for Polymer A was carried out except that tetrahydrofuran 102 was used.

Polymer I] The same procedure as for Polymer A was carried out except that 0.11Of silicon tetrachloride was used in place of 0.1759 of tin tetrachloride.

Examples 1 to 6 Comparative Examples 1 to 4 A stainless steel reactor equipped with a stirrer was charged with the solvents and monomers shown in Table 2, and then the rubbery polymers shown in Table 1 were added and dissolved. Dicumyl peroxide was added as a polymerization initiator and t-dodecyl mercaptan was added as a molecular weight regulator to this solution, and polymerization was carried out while maintaining the temperature at 110° to 120°C.

Polymerization was stopped when the conversion rate reached about 60%, and the residual monomer was then removed under reduced pressure, granulated using an extruder, and test pieces were molded using an injection molding machine (220° C.) to measure physical properties. Table 2 shows the results.

The rubber-modified graft thermoplastic resin using the rubbery polymer of the present invention is a well-balanced resin composition that has excellent impact resistance, molded appearance (gloss), and tensile strength. Example 4
In Example 5, the resin composition was particularly excellent in impact resistance, and in Example 5, the resin composition was particularly excellent in transparency.

Procedural amendment (method) November 1981 Commissioner of the Patent Office Mr. Kazuo Wakasugi1, Indication of the case 1982 Patent Application No. 1329902, Name of the invention Rubber-modified grafted thermoplastic resin composition 6, Make amendments Relationship with the Patent Case Patent Applicant Address 2-11-24 Tsukiji, Chuo-ku, Tokyo Name
Japan Synthetic Rubber Co., Ltd. Representative Hisashi Yoshimitsu 4, Agent 101 Address 2-42-5 Kanda Jimbocho, Chiyoda-ku, Tokyo
Date of amendment order: October 7, 1982 (Delivery date: October 26, 1982) 6. Specification subject to amendment (correction of ballpoint pen writing in table frame) Z Contents of amendment As shown in the attached sheet

Claims (1)

[Scope of Claims] In a butadiene copolymer obtained by reacting a random butadiene copolymer consisting of an aromatic compound and 1,3-butadiene with a tin halide compound, (1) a bonded vinyl of the polypolymer; Aromatic compound content is O~
(11) The vinyl bond content of the butadiene part of the Toden combined is between 10 and less than 30, (branched butadiene in which the bond in the one-width branch part is a tin-butadienyl bond); 98 to 60 parts by weight of a vinyl aromatic compound 1 or a mixture of a vinyl aromatic compound and at least one vinyl monomer copolymerizable with it are grafted to the ratio A of the system copolymer. Rubber-modified graft thermoplastic resin composition. (2) Mooney viscosity (to IL
)1-! 4 is 20 to 100, and the ratio M, /M, of the weighted average molecular weight (M, ) to the number average molecule El (11) is less than 2.5. Grafted thermoplastic composition. (3) The rubber-modified grafted thermoplastic resin composition according to claim (1), wherein the content of the bound vinyl aromatic compound in the butanene copolymer is 4 weight range or more and less than 15 weight range.